EPSTEIN BARR VIRUS LATENCY

EB病毒是一种人类疱疹病毒，可以潜伏感染， 体外永生化人B淋巴细胞。这种病毒会终生存在， 在免疫抑制的个体中可引起淋巴瘤。 虽然感染和潜伏期已经在体外进行了广泛的研究， 对体内潜伏感染知之甚少。这项建议的目的是 是表征EB病毒在体内的潜伏感染以及如何 这种潜伏期受到免疫抑制的干扰。 我们开发了一种高灵敏度的EB病毒DNA PCR检测方法，可以 我们可以在多达5x 10/7个未感染的细胞中检测到单个基因组。我们 已经使用该测定来测量在小鼠中病毒感染细胞的频率。 健康个体的外周血，并证明 这些细胞的表型（CD 23- B细胞）与 在体外，EBV感染的淋巴母细胞。我们打算进一步描述 细胞的细胞表面表型（活化的与静息的、记忆的） 相对于处女，成熟相对于BL/类似于生殖中心，B1相对于B2）。这 这些信息将鉴定体内EBV潜伏期靶细胞， 用于开发用于富集细胞群的方案， 病毒，然后可以使用RNA PCR测试病毒基因表达。 我们假设健康个体中的受感染细胞将被 休息和表达一组有限的潜在基因，以避免 免疫监视。免疫抑制后，这些细胞的频率 然而，不应该改变类似于典型EBV淋巴母细胞的细胞， 通常处于免疫监视下， 免疫母细胞性淋巴瘤现在将被检测出来这些研究报告将 与纽约市的移植部门合作进行 英格兰医学中心的长期目标是确定潜在的 免疫抑制患者发生EBV淋巴瘤的危险因素。

Epstein-Barr virus is a human herpesvirus that can latently infect and immortalize human B lymphocytes in vitro. The virus persists for life in vivo and can give rise to lymphoma in immunosuppressed individuals. Although infection and latency have been studied extensively in vitro, little is known about latent infection in vivo. The aim of this proposal is to characterize latent infection by Epstein-Barr virus in vivo and how that latency is perturbed by immunosuppression. We have developed a highly sensitive DNA PCR assay for EBV which allows us to detect a single genome in as many as 5x10/7 uninfected cells. We have used this assay to measure the frequency of virus infected cells in the peripheral blood of healthy individuals and to demonstrate that the phenotype of these cells is uniquely different (CD23- B cells) from that of in vitro, EBV infected lymphoblasts. We intend to further characterize the cell surface phenotype of the cells (activated vs. resting, memory vs. virgin, mature vs. BL/germinal center like, Bi vs. B2). This information will identify target cell(s) for EBV latency in vivo and be used to develop protocols for enriching cell populations that carry the virus, which can then be tested for viral gene expression using RNA PCR. We hypothesize that the infected cells in healthy individuals will be resting and expressing a limited set of latent genes, so as to avoid immunosurveillance. Upon immunosuppression the frequency of these cells should not change, however, cells resembling typical EBV lymphoblasts, normally under immunosurveillance and potential precursors for immunoblastic lymphoma, will now be detected. These studies will be carried out in collaboration with the transplantation unit at the New England Medical Center with the long term goal of identifying potential risk factors in immunosuppressed patients who develop EBV lymphoma.